I FOR ONE WILL NOW ALWAYS TOW TO 500ft ABOVE SLIP STREAM IN A HEAVY GLIDER-
no iffs or buts

About every 10 years/2000hr  tow pilots seem to go out of their way to raise
my stress levels to make sure I am awake and still on the ball.

My most recent one was Dec 30, 2010 and I was giving a CFI of a club his
first flight in a new 2 seater glider (AUW 710kg)  and he choose to climb
out just below slipstream.  Unfortunately the tow pilot was following his
ASI instead of attitude. We called for more speed and you guessed it a loop
which was not real bad but rope broke and we were left with a very
interesting low level return to the field having to go around a line of
trees. The alternative was a straight ahead to the lake and if they can land
on lakes in Sweden and fly next day then so can we in AUS.

There is a old saying "straight ahead to the hospital or left or right to
the cemetery" but when you are faced with a decision it is very tempting to
turn back trust me!!

Next day we discovered the pitot in tug was partly blocked (very very slow
at responding) by hornet nest.  If it was fully blocked then clearly it
rises to full scale as you climb and goes to zero on decent. Unfortunately
the tug pilot was never taught this.  Anyhow I am donating $8 auto pitot
cover for tug which should go on this week so never again should this happen

So what I am leading to is

1  Hence forth I will ALWAYS climb out just above the slip stream to say
500ft ESPECIALLY in heavy gliders
2  I believe SPLICED (joined) ropes have no place in gliding (This rope had
a SPLICE in it 1/3 the way to tug)..
3  Personally I would prefer to see a bowline knot at the glider end as they
are easier to redo when showing wear. I see it often happens that a worn
splice left in ropes far too long.  I understand little hard burnt knobs
should be sticking out from the splice and when they wear away the splice
should be REDONE. The end of the splice quickly becomes the ropes weak link
and not the tost weak link at other end which is what happened in this
incident.
4  Ropes MUST be end for ended early rather than later.
5  Tug pilots must once straight ahead is not an option go left or right of
track (obviously the downwind side of field) so glider has
less maneuvering to return to the field.
6  Tug pilots at beginning of each days towing should carefully check their
rope for condition, rejecting crap ropes and then the hook on person should
check for the rest of the day.
7  I read on this list one club replace ropes at 200flights and at least
they get no rope brakes.

My other problems from the past are an aerotow retrieve but the tow pilot
only had one magneto on and my only alternative was a Murray River landing.
 Another was the fabric of tug started coming off in strips heading down the
rope towards me in the glider.  I went to above slipstream (but rope still
came along the rope.  The cause of this was a leaking battery acid which
destroyed the fabric!!!

Remember the Swiss cheese is alive and well around all gliding activities.
 The problem is when the holes line up.

Ian McPhee
0428847642


On 12 April 2011 18:02, stephenk <[email protected]> wrote:

> Low tow has some advantages and is the GFA preferred way, but is certainly
> not mandatory.
>
> From the BGK:
> "When  the  tug  leaves  the  ground,  a  noticeable  slipstream  is
>  produced  from  its  wingtips  and  this
> combines with the propwash to produce considerable turbulence. If intending
> to carry out a high tow,
> a position above the slipstream is maintained as the combination climbs
> away. Remember that high
> tow  is,  by  definition,  just  above  the  slipstream,  not  above  the
>  tug.  The  slipstream  is  the  primary
> reference, not one of the fixtures on the tug.
> Note:    Slipstream  is  composed  mainly  of  wingtip  vortices.  It  is
>  only  present  in  flight,  not  on  the
> ground. The only tug-produced turbulence on the ground is propwash.
> If intending to carry out a low tow, maintain station above the slipstream
> until the tug is positively
> established in a climb. Then move gently but positively down through the
> turbulence of the slipstream
> until the turbulence ceases. The glider is now in the low-tow position.
> Once again the slipstream is the
> primary reference. Do not go too low in relation to the slipstream - it is
> not necessary. "
>
> Regards
> SWK
>
>
>
> On 12/04/2011 5:04 PM, Peter F Bradshaw wrote:
>
>> Hi Adam;
>>
>> Interesting. We are a mandatory low tow club. I thought that all clubs
>> in Australia were likewise.
>>
>> On Tue, 12 Apr 2011, Adam Woolley wrote:
>>
>>  High tow all the way, so much easier - and definitely gives you more
>>> options
>>> in the early stages of the tow.
>>>
>>> WPP
>>>
>>> -
>>>
>>
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